206. Reverse Linked List-LeetCode

class Solution {
public:
    ListNode* reverseList(ListNode* head) {
        ListNode* prev=NULL;
        ListNode* start=head;
        ListNode* node=head;
        while(node!=NULL)
        {
            start=node->next;
            node->next=prev;
            prev=node;
            node=start;
        }
        return prev;
    }
};